U.S. patent application number 17/606211 was filed with the patent office on 2022-08-04 for method for a data transmission between a first and a second module and system including mobile parts for carrying out the method.
This patent application is currently assigned to SEW-EURODRIVE GMBH & CO. KG. The applicant listed for this patent is SEW-EURODRIVE GMBH & CO. KG. Invention is credited to Zhidong HUA, Thomas SCHAFER, Josef SCHMIDT, Steffen STORCK, Andreas WANJEK.
Application Number | 20220247490 17/606211 |
Document ID | / |
Family ID | 1000006288021 |
Filed Date | 2022-08-04 |
United States Patent
Application |
20220247490 |
Kind Code |
A1 |
WANJEK; Andreas ; et
al. |
August 4, 2022 |
METHOD FOR A DATA TRANSMISSION BETWEEN A FIRST AND A SECOND MODULE
AND SYSTEM INCLUDING MOBILE PARTS FOR CARRYING OUT THE METHOD
Abstract
In a method for a data transmission between first and second
modules, and a system having mobile parts for performing the
method: the time bases of the first and second modules are
synchronized; transmitters of the first module emit a light signal
pulse individually one after the other and/or in numbered order in
a respective time range; the particular receiver of the second
module at which the strongest receive signal occurs is determined,
the particular time range and/or the number of the particular time
range being determined in which the strongest receive signal
occurs; the determined time range and/or the determined number
is/are transmitted from the second module to the first module; and
the transmitter of the first module associated with the determined
time range and/or to the determined number is determined and used
for the subsequent data transmission from the first module to the
second module.
Inventors: |
WANJEK; Andreas; (Waghausel,
DE) ; STORCK; Steffen; (Bruchsal, DE) ; HUA;
Zhidong; (Bruchsal, DE) ; SCHAFER; Thomas;
(Karlsdorf-Neuthard, DE) ; SCHMIDT; Josef;
(Graben-Neudorf, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SEW-EURODRIVE GMBH & CO. KG |
Bruchsal |
|
DE |
|
|
Assignee: |
SEW-EURODRIVE GMBH & CO.
KG
Bruchsal
DE
|
Family ID: |
1000006288021 |
Appl. No.: |
17/606211 |
Filed: |
April 2, 2020 |
PCT Filed: |
April 2, 2020 |
PCT NO: |
PCT/EP2020/025158 |
371 Date: |
October 25, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04B 10/1143
20130101 |
International
Class: |
H04B 10/114 20060101
H04B010/114 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 25, 2019 |
DE |
10 2019 002 958.5 |
Claims
1-11. (canceled)
12. A method for a data transmission between a first module and a
second module, the first module including transmitters, the second
module including transmitters, comprising: (a) synchronizing a time
basis of the first module with a time basis of the second module;
(b) emitting, by the transmitters of the first module, a light
signal pulse individually one after the other and/or in numbered
order in a respective time range; (c) determining a particular
receiver of the second module at which a strongest receive signal
occurs and determining a particular time range and/or a number of
the particular time range in which the strongest receive signal
occurs (d) transmitting the determined time range and/or the
determined number from the second module to the first module; and
(e) determining the transmitter of the first module associated with
the determined time range and/or the determined number and using
the determined transmitter of the first module for subsequent data
transmission from the first module to the second module.
13. The method according to claim 12, wherein the transmitters of
the first and second modules are arranged as light transmitters,
the first module includes light-sensitive receivers, and the second
modules include light-sensitive receivers.
14. The method according to claim 12, wherein the time range
includes a time slot.
15. The method according to claim 12, wherein the determining in
(c) is performed by a control electronics of the second module
while executing the emitting in (b).
16. The method according to claim 12, wherein the determining in
(e) is performed by a control electronics of the first module.
17. The method according to claim 12, wherein at least the emitting
in (b), the determining in (d), and the determining in (e) are
performed recurrently over time.
18. The method according to claim 12, further comprising: (f)
emitting, by the transmitters of the second module, a light signal
pulse individually one after the other and/or in numbered order in
a respective time range; (g) determining a respective receiver of
the first module at which a strongest receive signal occurs and
determining a particular time range and/or a number of the
particular time range in which the strongest receive signal occurs;
(h) transmitting the determined time range and/or the determined
number from the first module to the second module; and (i)
determining the transmitter of the second module associated with
the determined time range and/or the determined number and using
the determined transmitter of the second module for subsequent data
transmission from the second module to the first module.
19. The method according to claim 18, wherein the emitting in (f),
the transmitting in (h), and the determining in (i) are performed
recurrently over time.
20. The method according to claim 18, wherein the determining in
(g) is performed while executing the emitting (f).
21. The method according to claim 12, wherein the transmitters of
the first module have a preferred direction for light emitted
thereby and are arranged with different and non-parallel
orientations, light cones emitted by the transmitters of the first
module not being aligned in parallel, the transmitters of the
second module have a preferred direction for light emitted thereby
and are arranged with different and non-parallel orientations,
light cones emitted by the transmitters of the second module not
being aligned in parallel.
22. The method according to claim 12, further comprising
transmitting a message after the determining in (e).
23. The method according to claim 18, further comprising
transmitting a message after the determining in (e) and/or after
the determining in (i).
24. The method according to claim 13, wherein the transmitters
include LEDs and the receivers include a light-sensitive component,
a photo transistor, and/or a photodiode.
25. The method according to claim 12, wherein the second module is
located within a transmission range of at least one transmitter of
the first module, and the first module is located within a
transmission range of at least one transmitter of the second
module.
26. The method according to claim 12, wherein light signal pulses
emitted by the transmitters in (b) are all modulated in the same
manner so that each light signal pulse includes a same message.
27. A system adapted to perform the method recited in claim 12,
comprising: a plurality of mobile parts, each mobile part including
at least one module, each module including a control electronics,
transmitters connected to the control electronics of the module,
and receivers connected to the control electronics of the
module.
28. The system according to claim 27, wherein the transmitters are
arranged as light transmitters, and the receivers are arranged as
light sensitive receivers.
29. The system according to claim 27, wherein the mobile parts are
adapted to be moved on a driving surface of the system, and each
module has a same distance from the driving surface.
30. The system according to claim 27, wherein the transmitters of
each module are arranged along a flat, bent curve and are adapted
to emit light cones having different orientations.
31. The system according to claim 27, wherein a first one of the
mobile parts and a third one of the mobile parts are arranged so
that no signal transmission is performable between the first one of
the mobile parts and the third one of the mobile parts, the first
one of the mobile parts and a second one of the mobile parts being
arranged to perform a data transmission between the first one of
the mobile parts and the second one of the mobile parts, the second
one of the mobile parts and the third one of the mobile parts being
arranged to perform a data transmission between the second one of
the mobile parts and the third one of the mobile parts.
32. The system according to claim 31, wherein the first one of the
mobile parts, the second one of the mobile parts, and the third one
of the mobile parts are adapted to perform the method recited in
claim 12 between the modules of the first one of the mobile parts
and the second one of the mobile parts and between the modules of
the second one of the mobile parts and the third one of the mobile
parts.
33. The system according to claim 31, wherein an obstacle
interposed between the first one of the mobile parts and the third
one of the mobile parts and/or and excessive distance between the
first one of the mobile parts and the third one of the mobile parts
prevents the signal transmission between the first one of the
mobile parts and the third one of the mobile parts.
34. A system, comprising: a plurality of mobile parts, each mobile
part including at least one module, each module including a control
electronics, transmitters connected to the control electronics of
the module, and receivers connected to the control electronics of
the module; wherein the system is adapted to perform the method
recited in claim 12.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a method for a data
transmission between a first and a second module and to a system
that includes mobile parts for carrying out the present method.
BACKGROUND INFORMATION
[0002] In certain conventional systems, a receiver receives the
signal from a transmitter for a data transmission.
[0003] U.S. Patent Application Publication No. 2011/0069971
describes a method for a data transmission using visible light.
[0004] German Patent Document No. 601 00 824 describes a method for
a transmission signal adjustment in an optical free space
transmission system.
[0005] German Patent Document No. 10 2015 205 220 describes a
tracking system for tracking a carrier of a mobile communications
unit.
[0006] U.S. Patent Application Publication No. 2009/0022499
describes a method for setting up a communications connection using
visible light.
[0007] U.S. Patent Application Publication No. 2009/0316679
describes a wireless broadcast network.
SUMMARY
[0008] Example embodiments of the present invention provide for a
data transmission that features low interference and/or a low error
rate.
[0009] According to an example embodiment of the present invention,
in a method for a data transmission between a first and a second
module, the first module has transmitters, e.g., for light, and,
e.g., light-sensitive receivers, and the second module has
transmitters, e.g., for light, and, e.g., light-sensitive
receivers. In a first method step, the time basis of the first
module is synchronized with the time basis of the second module. In
a second method step, the transmitters of the first module emit a
light signal pulse individually one after the other and/or in
numbered order in a respective time range, e.g., time slot. The
respective receiver of the second module is determined at which the
strongest receive signal occurs, e.g., by a control electronics of
the second module, e.g., while executing the second method step,
and the particular time range, e.g., time slot, and/or the number
of the particular time range is/are determined in which the
strongest receive signal occurs. In a third method step, the
determined time range and/or the determined number is/are
transmitted from the second module to the first module. In a fourth
method step, the transmitter of the first module associated with
the determined time range and/or the determined number is
determined, e.g., by a control electronics of the first module, and
used for the subsequent data transmission from the first module to
the second module. At least the second, third, and fourth method
steps, for example, are carried out in a recurrent manner over
time.
[0010] This has the advantage that a data transmission that has
minimal interference and noise is achievable. This is because the
use of transmitters that emit light, e.g., more strongly in a
preferred direction than in another direction, and the use of
receivers that likewise have a preferred direction in their
sensitive range allows for a directional transmission of signals.
Light-emitting interference transmitters are thus suppressed,
provided they are not situated in the used transmission space
region that includes the connecting line between transmitter and
receiver. In addition, the particular transmitter of the first
module and the particular receiver of the second module that allow
for a signal transmission featuring an optimal signal-to-noise
ratio are selected in a recurring manner over time. This selected
pair induces the greatest receive amplitude in the receiver, i.e.,
the best signal-to-noise ratio. The connecting line between the
transmitter and the receiver of the pair extends at least
substantially in parallel with the preferred direction of the
transmitter and with the preferred direction of the receiver. Since
a movement of the mobile parts changes the orientation of the
modules relative to one another and thus the deviation of the
preferred direction from the direction of the connecting line, the
pair is always determined anew in a recurrent manner over time.
[0011] According to example embodiments: In a fifth method step,
the transmitters of the second module emit, individually one after
the other and/or in numbered order, a light signal pulse in a
respective time range, in particular time slot; the respective
receiver of the first module is determined in which the strongest
receive signal occurs, e.g., while the fifth method step is
executed, and the particular time range, e.g., time slot, and/or
the number of the particular time range in which the strongest
receive signal occurs is/are determined; then, in a sixth method
step, the determined time range and/or the determined number is/are
transmitted from the first module to the second module; next, in a
seventh method step, the transmitter of the second module
associated with the determined time range and/or the determined
number is determined and used for the subsequent data transmission
from the second module to the first module. At least the fifth,
sixth, and seventh method steps are, for example, carried out in a
recurrent manner over time. This offers the advantage that a
transmission that is similarly low in interference can be set up
also for the return channel because here, too, the particular pair
that allows for the best signal-to-noise ratio is able to be
selected.
[0012] According to example embodiments, the transmitters of the
first module have a preferred direction for the light they emit and
are situated with different, and thus, for example, non-parallel,
orientations. For example, the light cones emitted by the
transmitters of the first module are not aligned in parallel. The
transmitters of the second module have a preferred direction for
the light they emit and are situated with different, e.g.,
non-parallel, orientations. For example, the light cones radiated
by the transmitters of the second module are not aligned in
parallel. This offers the advantage that interfering light sources
can be suppressed. This is because the communications channel
requires only a limited space region.
[0013] According to example embodiments, a message is transmitted
after the fourth and/or after the seventh method step. This has the
advantage that the transmitter and receiver pairs having the best
signal-to-noise ratio and messages are selected, which means that
messages are transmittable in a manner that is low in errors and
safe from interference.
[0014] According to example embodiments, the transmitters are
arranged as LEDs and the receivers are arranged as a
light-sensitive component, e.g., a photo transistor or a
photodiode. This has the advantage that a directional transmission
of light may be carried out and also a receiving with a preferred
direction.
[0015] According to example embodiments, the second module is
located within the transmission range of at least one transmitter
of the first module, and the first module is located within the
transmission range of at least one transmitter of the second
module. This offers the advantage that a message transmission is
able to be carried out.
[0016] According to example embodiments, the light signal pulses
emitted by the transmitters in the second method step are all
modulated in the same manner so that each light signal pulse
includes the same message. This offers the advantage that on the
one hand, the training sequence carried out in the second method
step makes it possible to determine the pair having the best
signal-to-noise ratio and that on the other hand, a message is
still transmittable during this time. It is disadvantageous that
each transmitter of the first module consecutively emits the same
light signal pulse onto which the same message is modulated. The
data transmission rate during the training sequence is therefore
lower than in the usual data transmission. Thus, the more
transmitters the first module has and the shorter the light signal
pulses, the lower the data transmission rate.
[0017] However, if the first module has only four transmitters, for
example, and the light signal pulse takes up nearly a fourth of the
total duration of the training sequence, that is to say, of the
second method step, then a data transmission rate that is slightly
lower than one-fourth the other data transmission rate is still
achievable. Given N transmitters, a data transmission rate is
therefore achievable that is slightly lower than the Nth part of
the other data transmission rate.
[0018] According to an example embodiment of the present invention,
in a system having mobile parts for carrying out the method
described herein, each one of the mobile parts has at least one
module provided with transmitters, e.g., for light, and, e.g.,
light-sensitive receivers, the transmitters and receivers of the
respective module, e.g., being connected to a control electronics
of the respective mobile part.
[0019] This has the advantage that the mobile part is able to
transmit messages to the other mobile part and a mutually
influenced operation can thus be carried out. On the one hand, this
makes it possible to avoid a collision and on the other hand, it is
possible to jointly carry out an intralogistics transport task.
Information is transmittable in addition. Because of the
directional transmission, however, messages can also be forwarded
from a first mobile part via a second mobile part to a third mobile
part, even if no communications link exists between the first and
the third mobile parts. It is therefore also possible to send
messages to mobile parts that are located at a great distance or to
send messages to mobile parts to which no direct, i.e., straight,
line of sight exists. A low-noise communication around an obstacle
is enabled as a result.
[0020] According to example embodiments, the mobile parts are able
to be moved on a driving surface of the system and each one of the
modules has the same distance from the driving surface. This offers
the advantage that the message transmission can be carried out in a
defined plane or surface that has a constant distance from the
driving surface.
[0021] According to example embodiments, the transmitters of each
module are situated along a flat bent curve, and the light cones
emitted by the transmitters have a different orientation. This has
the advantage that a large solid angle range is able to be covered
even when using transmitters that emit narrow radiation, i.e., emit
into a small solid angle.
[0022] According to example embodiments, no signal transmission is
able to take place between a first and a third mobile part, e.g.,
because of an interposed obstacle and/or an excessive distance. A
data transmission is carried out between the first and a second
mobile part and between the second and the third mobile part. The
method described herein is carried out between the modules of the
first and second mobile part, and the method is carried out between
the modules of the second and third mobile part. This has the
advantage that if the distance is too great or if obstacles are
interposed, bridging for light is possible with the aid of an
interposed second mobile part which has two modules, so that the
information received by the first one of the two modules from a
module of the first mobile part is able to be transmitted further
to the third mobile part, e.g., its module, with the aid of the
second of the two modules of the second mobile part.
[0023] Further features and aspects of example embodiments of the
present invention are described in greater detail below with
reference to the appended schematic Figures
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 schematically illustrates a first module 1 and a,
e.g., identically configured second module 4.
[0025] FIG. 2 illustrates the transmitted and received signal
characteristics in a schematic representation.
DETAILED DESCRIPTION
[0026] As schematically illustrated in the Figures, first module 1
has four transmitters, e.g., LEDs, whose emittable light cone is
aligned in different directions.
[0027] Assigned to each transmitter is a respective receiver, e.g.,
a photodiode or photo transistor, whose sensitive range has a shape
similar to the corresponding light cone and thus also has a
preferred direction. In the simplest case, the preferential
direction of the light cone of the respective transmitter is
parallel to the preferred direction of the respective receiver.
[0028] The transmitters are, for example, situated along a flat
curve, e.g., a circular path, and are set apart from one another at
regular intervals along this curve.
[0029] The arrangement of second module 4 is, for example,
identical with that of first module 1.
[0030] First module 1 is situated on a first mobile part and second
module 4 is situated on a second mobile part, which moves
independently, e.g., in an automatically guided manner, relative to
the first mobile part in a system.
[0031] To carry out the communication, the best transmission
channel is determined in a recurrent manner over time in that the
transmitters of first module 1 emit light pulses and the respective
receiver that detects the greatest receive amplitude is determined.
Thus, a transmission channel is set up between this receiver and
the strongest transmitter for this receiver. This determination and
setup are repeated in time.
[0032] This is described in greater detail in the following
text.
[0033] In a chronologically deterministic raster, signals are
transmitted from first module 1 and received by second module 4, or
vice versa.
[0034] To this end, a training signal characteristic is appended to
a respective message, characterized by time range t_TX_DATA.
[0035] The training signal includes four consecutive time segments,
e.g., time slots, and another LED of first module 1 emits a light
signal pulse in each one of the time slots. The energy and time
period of each of the light pulse signals are of the same
magnitude.
[0036] According to FIG. 1, a first transmitter of first module 1
thus emits a light signal pulse in a first time slot t_int1, a
second transmitter of first module 1 emits a light signal pulse in
a second time slot t_int2, a third transmitter of first module 1
emits a light signal pulse in a third time slot t_int1, and a
fourth transmitter of first module 1 emits a light signal pulse in
a fourth time slot t_int4.
[0037] Signal E received by one of the receivers of second module 4
is illustrated in FIG. 2 and exhibits a maximum in the third light
signal pulse. The setup of a communications channel between the
third transmitter and the receiver would therefore be possible.
However, the receive signals of the other receivers of second
module 4 are evaluated as well. The communications channel is then
set up between the third transmitter and the particular receiver
that has received the strongest signal. If need be, a different
transmitter is used instead of the third transmitter if it has
induced a stronger signal in one of the receivers.
[0038] Put another way, the particular transmitter-receiver pair
that is able to generate the strongest receive signal is
determined.
[0039] As illustrated in FIG. 2, the first message packet that is
sent from first module 1 to second module 4 is therefore followed
by a first training signal with the four light signal pulses of the
transmitters of first module 1.
[0040] In the process, the particular receiver whose receive signal
had the highest amplitude is determined. The transmitter associated
with this highest amplitude is then determined, which is the third
transmitter in FIG. 2, and this information pertaining to the
identity of the associated transmitter, i.e., the third
transmitter, is transmitted to first module 1 in the next message
packet that is sent from the second to the first module 1.
[0041] The corresponding communications channel for the
transmission of the messages from the first to the second module is
set up in this manner. In the example, the third transmitter of
first module 1 and the determined receiver of second module 4 are
thus used for the message transmission from the first to the second
module.
[0042] The pair to be used for the return channel is determined
next:
[0043] To this end, second module 4 also emits a training signal,
which includes the light signal pulses to be sent individually by
the transmitters.
[0044] Now, the particular receiver of first module 1 that has
received the strongest amplitude may then be determined again in
this manner. At the same time, the particular transmitter of second
module 4 that has emitted this strongest signal is able to be
determined in the process.
[0045] The best transmitter-receiver pair is thereby also
determined for the return channel.
[0046] In the example, this is the second transmitter of second
module 4 and the particular receiver of first module 1 that detects
the strongest receive signal.
[0047] The pairs determined in this manner are used for the
subsequent transmission of the messages until the currently best
transmitter-receiver pairs are determined again with the aid of
training signals.
[0048] Only the determined transmitters and receivers are used when
transmitting the messages. The other transmitters and receivers
remain unused. Interference effects on other mobile parts or from
other mobile parts are preventable as a result. This is because
only the particular light cone 3 that has been generated by the
transmitter and is directed toward the receiver of the other module
(1, 4) is used for the message transmittal. The transmitter thus
radiates into as few other spatial areas as possible in which
further modules of other mobile parts are being moved, for
example.
[0049] In further exemplary embodiments, the light signal pulses
themselves are also modulated so that the same message is
transmitted by each one of the light signal pulse signals in the
training signal characteristic, but, e.g., into different preferred
directions. The receivers thus receive this message with more or
less noise depending on the receive amplitude. However, after the
strongest receive signal has been determined, even the message
transmitted with this particular signal can be detected with few
errors.
[0050] In further exemplary embodiments, each transmitted message
is followed by a training signal so that an optimal updating takes
place when the currently best transmitter-receiver pairs are
determined.
LIST OF REFERENCE CHARACTERS
[0051] 1 first module [0052] 2 light transceiver, e.g., LED with a
photodiode or photo transistor [0053] 3 light cone [0054] 4 second
module [0055] E reception [0056] t_TX_DATA message transmission
[0057] t_int1 first time slot [0058] t_int2 second time slot [0059]
t_int1 third time slot [0060] t_int4 fourth time slot
* * * * *